Controller failure diagnosing device and method

Abstract

The controller failure diagnosing device and method may provide a controller failure diagnosing technique that may diagnose a failure in the controller using the characteristics of the controller when using a motor and an inverter. In particular, there may be provided a controller failure diagnosing device and method capable of diagnosing a failure in a controller by comparing the measured 3-phase voltage of the motor and the calculated controller output voltage or by determining entry into an unstable control area condition at an early stage.

What is claimed is: 
     
         1 . A controller failure diagnosing device, comprising:
 a voltage measurer implemented as a detection circuit, and configured to measure a 3-phase voltage of a motor at an inverter output terminal connected to the motor;   a voltage calculator configured to inversely calculate a d-axis control voltage and a q-axis control voltage corresponding to an output voltage of a controller driving the motor, based on a design parameter of the controller and an input current of the controller including a d-axis reference current, a q-axis reference current, a d-axis feedback current, and a q-axis feedback current; and   a failure diagnoser implemented as a comparison circuit, and configured to diagnose a failure in the controller by comparing the measured 3-phase voltage and the calculated output voltage,   wherein if the controller is diagnosed as the failure, the failure diagnoser determines whether a rotating speed and an output torque of the motor are included in a preset control area condition, generates a switching signal to 3-phase short according to a result of the determination, and transfers the switching signal to the controller.   
     
     
         2 . The controller failure diagnosing device of  claim 1 , wherein the controller includes a first controller generating the d-axis control voltage and a second controller generating the q-axis control voltage, and wherein the first controller and the second controller include a proportional controller and an integral controller, respectively. 
     
     
         3 . The controller failure diagnosing device of  claim 2 , wherein if an output voltage of the integral controller is not varied in response to a variation in a current error input to the controller, the failure diagnoser diagnoses the controller as a failure. 
     
     
         4 . The controller failure diagnosing device of  claim 2 , wherein if an output voltage of the proportional controller is not reduced even after a specific time when a current error input to the controller converges, the failure diagnoser diagnoses the controller as a failure. 
     
     
         5 . The controller failure diagnosing device of  claim 1 , wherein if an output voltage of the controller is higher than a voltage of a battery supplying a direct current (DC) voltage to the inverter, the failure diagnoser diagnoses the controller as a failure. 
     
     
         6 . The controller failure diagnosing device of  claim 1 , wherein if the rotating speed and the output torque of the motor are in a normal state, and do not correspond to a first quadrant mode or a third quadrant mode among four quadrant operation modes, the failure diagnoser diagnoses the controller as a failure. 
     
     
         7 . The controller failure diagnosing device of  claim 6 , wherein the first quadrant mode and the third quadrant mode are set as a normal area of the integral controller. 
     
     
         8 . The controller failure diagnosing device of  claim 1 , wherein if determining that the rotating speed and output torque of the motor are not included in the control area condition, the failure diagnoser generates the switching signal. 
     
     
         9 . The controller failure diagnosing device of  claim 1 , wherein the 3-phase short is a state in which a switching operation is controlled so that an upper switching element or a lower switching element for each phase of the inverter is simultaneously turned on. 
     
     
         10 . A controller failure diagnosing method, comprising:
 measuring a 3-phase voltage of a motor at an inverter output terminal connected to the motor;   inversely calculating a d-axis control voltage and a q-axis control voltage corresponding to an output voltage of a controller driving the motor, based on a design parameter of the controller and an input current of the controller including a d-axis reference current, a q-axis reference current, a d-axis feedback current, and a q-axis feedback current; and   diagnosing a failure in the controller by comparing the measured 3-phase voltage and the calculated output voltage,   wherein, if the controller is diagnosed as the failure, the diagnosing of the failure in the controller includes determining whether a rotating speed and an output torque of the motor are included in a preset control area condition, generating a switching signal to 3-phase short according to a result of the determination, and transferring the switching signal to the controller.   
     
     
         11 . The controller failure diagnosing method of  claim 10 , wherein the controller includes a first controller generating the d-axis control voltage and a second controller generating the q-axis control voltage, and wherein the first controller and the second controller include a proportional controller and an integral controller, respectively. 
     
     
         12 . The controller failure diagnosing method of  claim 11 , wherein if an output voltage of the integral controller is not varied in response to a variation in a current error input to the controller, the diagnosing of the failure in the controller diagnoses the controller as a failure. 
     
     
         13 . The controller failure diagnosing method of  claim 11 , wherein if an output voltage of the proportional controller is not reduced even after a specific time when a current error input to the controller converges, the diagnosing of the failure in the controller diagnoses the controller as a failure. 
     
     
         14 . The controller failure diagnosing method of  claim 10 , wherein if an output voltage of the controller is higher than a voltage of a battery supplying a direct current (DC) voltage to the inverter, the diagnosing of the failure in the controller diagnoses the controller as a failure. 
     
     
         15 . The controller failure diagnosing method of  claim 10 , wherein if the rotating speed and the output torque of the motor are in a normal state, and do not correspond to a first quadrant mode or a third quadrant mode among four quadrant operation modes, the diagnosing of the failure in the controller diagnoses the controller as a failure. 
     
     
         16 . The controller failure diagnosing method of  claim 15 , wherein the first quadrant mode and the third quadrant mode are set as a normal area of the integral controller. 
     
     
         17 . The controller failure diagnosing method of  claim 10 , wherein if determining that the rotating speed and output torque of the motor are not included in the control area condition, the diagnosing of the failure in the controller generates the switching signal. 
     
     
         18 . The controller failure diagnosing method of  claim 10 , wherein the 3-phase short is a state in which a switching operation is controlled so that an upper switching element or a lower switching element for each phase of the inverter is simultaneously turned on.